The urogenital area harbors a complex microbial ecosystem comprising more than 50 different bacterial species (Hill et al., Scand. J. Urol. Nephrol. 1984; 86 (suppl.) 23-29). The dominating species for fertile women in this area are lactic acid producing bacteria belonging to the genus Lactobacillus. These lactic acid producing members are important for retaining a healthy microbial flora in these areas, and act as probiotic bacteria with an antagonistic effect against pathogenic microbial species. Lactic acid producing bacteria inhibit growth and colonization by other microorganisms by occupying suitable niches for colonization, by forming biofilms and competing for available nutrients, thereby excluding colonization by harmful microorganisms. Also, the production of hydrogen peroxide, specific inhibiting substances, such as bacteriocines, and organic acids (including lactic acid and acetic acid) that lower the pH, inhibit the growth and colonization by other microorganisms.
The microbial ecosystem of a healthy individual can be disturbed by the use of antibiotics, during hormonal changes, such as during pregnancy or use of contraceptives with estrogen, during menstruation, after menopause, in people suffering from diabetes etc. Also, microorganisms may spread from the anus to the urogenital area, this result in a disturbance of the normal microbial flora and leaves the individual susceptible to microbial infections such as vaginitis, candida infections, urinary tract infections and skin infections. Microorganisms commonly associated with these kinds of infections belong to the genera Escherichia, Enterococcus, Pseudomonas, Proteus, Klebsiella, Streptococcus, Staphylococcus, Gardnerella and Candida. Women are at particular risk due to their shorter distance between the anus and the urogenital tract; specially at risk are young women, who not yet have a well developed microflora in the urogenital area and older women, who in most cases no longer have a protective flora.
Similarly to the urogenital area, the skin is colonized by an array of organisms, which forms its normal flora. The numbers and identity of the organisms vary between different skin sites. This, together with the skin's structural barrier, provides the host with an excellent defense against invading microbes. The number of bacteria on the skin varies from a few hundred per cm2 on the arid surfaces of the forearm and back, to tens of thousands per cm2 on the moist areas such as the axilla and groin. This normal flora plays an important role in preventing foreign organisms from colonizing the skin, but it too needs to be kept in check, in order to avoid skin infections.
Staphylococcus aureus is the most common cause of minor skin infections, such as boils or abscesses, as well as more serious post-operative wound infection. Treatment involves drainage and this is usually sufficient for minor lesions, but antibiotics may be given in addition when the infection is severe and the patient has fever.
Toxic shock syndrome is a systemic infection caused by S. aureus strains which produce toxic shock syndrome toxin. The disease came to prominence through its association with tampon use by healthy women, but it is not confined to women and can occur as a result of S. aureus infection at non-genital sites.
Other common skin infections are caused by Streptococcus pyogenes (group A streptococci). The organisms are acquired through contact with other people with infected skin lesions and may first colonize and multiply on normal skin prior to invasion through minor breaks of the epithelium and the development of lesions.
Treatment with penicillin or erythromycin may be necessary to combat the infection.
Candida likes skin sites which are moist and warm and also rapidly colonizes damaged skin. Hence, the relative dryness of most areas of skin prevents the growth of Candida, which therefore are found in low numbers on healthy skin. Candida also colonizes the oral and vaginal mucosa and over-growth may result in disease in these sites. C. albicans is associated with diaper dermatitis. A study has shown that C. albicans induced lesions are remarkably influenced by pH, a lower skin pH giving less lesions (B. Runeman, Acta Derm Venereol 2000; 80: 421-424).
One way to reduce the problems with the kind of infections described above is to have a good personal hygiene. However, excessive use of cleaning agents not only decreases the amount of harmful microbes, but can harm the beneficial microbial flora, again render it susceptible for pathogenic species to colonize and cause infections. Alternatively, administration of lactic acid producing bacteria to the urogenital area and the skin, in order to out-compete pathogenic species and facilitate reestablishment and maintenance of a beneficial microbial flora in these areas, has been found to be a successful means to treat and prevent microbial infections
It has been suggested that lactic acid producing bacteria can be delivered via absorbent products, such as diapers, sanitary napkin, incontinence guards, panty liners and tampons, as described in, for example, WO 92/13577, WO 97/02846, WO 99/17813, WO 99/45099 and WO 00/35502.
Other ways of delivering the lactic acid producing bacteria have also been suggested, such as a hygiene tissue that allows both cleaning and caring of the skin and urogenital area and delivery of probiotic lactic acid producing bacteria, for example, WO 04/060416.
A major problem with providing products intended to be used for transfer of lactic acid producing bacteria, is that the bacteria have to retain viability during transport and storage of the products. Lactic acid producing bacteria rapidly lose viability under semi moist conditions, and it is therefore important that the bacteria are not exposed to moisture during storage. One way to partly overcome this problem in absorbent products provided with lactic acid producing bacteria has been to supply the products with the bacteria, drying said products to remove most of the moisture in them and providing the product in moisture impervious packages (W099/17813).
WO 00/61201 discloses a sanitary product containing an effective amount of a viable, non-pathogenic, probiotic bacterium, such as Bacillus coagulans, or an extracellular product thereof.
EP 1140226 describes the combination of a pH regulating substance in the form of a partially neutralized superabsorbent material with lactic acid-producing bacteria.
In view of the prior art there is still a need for sanitary articles with an improved prebiotic and/or probiotic effect, which articles are easy to store and transport.